Gut and saliva microbiota changes after taking Bacillus coagulans probiotics

Analysis of the Gut Microbiota Composition After Consumption of Probiotic Bacteria

Not applicable Interventional Lund University · NCT07046897

We will test whether taking a Bacillus coagulans probiotic for 14 days changes the bacteria in stool and saliva of healthy adults aged 18–65.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorLund University Academic / other
Locations1 site (Lund)
Trial IDNCT07046897 on ClinicalTrials.gov

What this trial studies

Healthy adults aged 18–65 will take a freeze-dried Bacillus coagulans probiotic daily for 14 days and collect saliva and fecal samples before and after the intervention. Samples will be frozen immediately and analyzed at Lund University using Illumina MiSeq sequencing and the QIIME2 pipeline to measure species composition, diversity, and relative abundance. People with gastrointestinal disease, autoimmune conditions, recent antibiotic use, or who consume other probiotic products or fermented foods are excluded. The study asks whether the probiotic produces changes in microbiota composition that would be considered beneficial.

Who should consider this trial

Good fit: Healthy adults aged 18–65 who are not on antibiotics, do not have gastrointestinal or autoimmune diseases or immune-suppressing conditions, and agree to avoid other probiotic or fermented foods during the study.

Not a fit: People with diagnosed GI or autoimmune diseases, significant immune deficiency, recent antibiotic use, or those already using other probiotic products are unlikely to receive benefit from this healthy-volunteer study.

Why it matters

Potential benefit: If successful, the results could support using Bacillus coagulans to beneficially shift saliva and gut microbiota in healthy people and guide future research for clinical applications.

How similar studies have performed: Previous probiotic research has produced mixed results—some trials report microbiota changes while others do not—and evidence specific to Bacillus coagulans in healthy adults remains limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

• You must be 18-65 years of age.

Exclusion Criteria:

* Participants must not be diagnosed with gastrointestinal diseases, autoimmune diseases or have diseases or medications that cause immune deficiency such as MS, type 1 diabetes, cancer or HIV.
* Participants must not have taken antibiotics in the month before or during the study.
* Participants must not consume other probiotic products or fermented foods during the study.

Where this trial is running

Lund

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Microbiota Analysis in Healthy SubjectsProbioticsMicrobiota compositionSalivaFaecesHealthy individuals
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.